Generators of this type are used particularly in nuclear power stations, where the vaporization of water constituting the secondary fluid is assured by contact with a bundle of tubes in which flows a primary fluid, heated by the nuclear reactor. To avoid "water-hammer" effects in the supply pipes wherein the water circulates, it is essential that the distributor should remain constantly full of water in order not to enclose a vapor pocket during its filling. During the normal operation of the steam generator, the water distributor is covered by the mass of water already present in the generator and no "water-hammer" effect is to be feared. However, during certain so-called "transient" phases of operation, it may happen that the distributor is no longer covered, and there is then a risk of it being completely emptied so that, if it is resupplied with cold water, a water hammer can occur in the pipes.
To avoid this drawback, a distributor structure has been proposed preventing the confinement of a vapor pocket. In such a construction, as described, e.g., in the French Patent published under 2,333,200, the distributor is constituted by an angular duct furnished at its top portion with curved tubes through which the feed water flows.
However, such a structure is relatively costly, due to the expense of fabricating curved tubes and of machining the distributor duct.
It is an object of the present invention to provide an improved distributor of very simple construction which can be formed from standard elements and has a relatively low manufacturing cost.